Hi, We have our system setup such that all interaction is done through co-processors. We update the database via a co-processor (it has the appropriate logic for dealing with concurrent access to rows), and we also query/aggregate via co-processor (since we don't want to send all the data over the network).
This generally works very well. However, some times one of the region servers will "pause". This doesn't appear to be a GC pause since it still serves up the UI, and adds occasional messages to the log regarding the LRU. The only thing I've found is that when I check the server that's causing the problem (easy to tell, since all the "working" servers have a low load, and the problem server has a higher load), I can see that there are a number of execCoprocessor requests that have been executing for much longer than they should. I want to know more details about the specifics of those requests; Is there an API I can use that will allow my coprocessor requests to be tracked more functionally? Is there a way to hook into the UI so I can provide my own list of running processes? Or would I have to write that all myself? I am using HBase 0.92.1, but will be upgrading to 0.94.1 soon. Thanks in advance! --Tom
